theorem Th41:
for
n being
Nat for
C being
Simple_closed_curve for
i,
j,
k being
Nat st 1
< j &
j <= k &
k < len (Gauge (C,n)) & 1
<= i &
i <= width (Gauge (C,n)) &
n > 0 &
(Gauge (C,n)) * (
j,
i)
in Upper_Arc (L~ (Cage (C,n))) &
(Gauge (C,n)) * (
k,
i)
in Lower_Arc (L~ (Cage (C,n))) holds
LSeg (
((Gauge (C,n)) * (j,i)),
((Gauge (C,n)) * (k,i)))
meets Upper_Arc C